Controller for electric motor driven apparatus



. 17, 1954 c. P. FELDHAUSEN CONTROLLER FOR ELECTRIC MOTOR DRIVEN APPARATUS Filed March 10, 1952 Patented Aug. 17, 1954 CONTROLLER FOR ELECTRIC MOTOR DRIVEN APPARATUS Cyril Feldhausen, Wauwatosa, Wis, assignmto Cutler-Hammer, Inc., Milwaukee, Wis., a

corporation of Delaware Application March 10, 1952, Serial No. 275,750

v5 Claims.

This invention relates to improvements in con strollers for electric motor driven apparatus.

Controllers embodyin the invention are especially advantageous .for control of printing presses but are not limited to such application.

A primary object is to provide a controller of the class described which affords inching of the motor for a constant predetermined time interval following momentary closure of the inch button.

Another object is to provide a controller of the class described which uses a time delay relay to interrupt the inching movement after a predetermined length of time.

Another object is to provide a controller of the class described which affords a predetermined minimum length of inching time.

Another object is to provide a controller of the class described which utilizes a main power contactor having an auxiliary contact whose movement begins after a predetermined time interval following closure of the main power contacts.

Another object .is to provide .a controller of the class described which utilizes a main power electromagnetic contactor having a normally closed auxiliary contact operable to effect deenergization of said contactor but which remains closed for a time interval following initial energization of the magnet coil to insure complete seating of the main contacts on every operation of said contactor.

The novel features which I consider characteristic of 'my invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be un derstood from the following description of a specific embodiment when read in connection with the accompanying drawing which shows schematically and diagrammatically a preferred embodiment of the invention.

Referring to the drawing, the same shows a polyphase slip ring induction motor M having its primary P supplied from lines L L and L through contacts 1*, l and 11 of a main contactor F which is of the four pole electromagnetically operated type. The secondary of motor M has for its circuit speed regulating resistors r r and r each resistor havin one of its ends attached to said secondary while the other ends of such resistors are connected together as at point 2 Resistors T, r and r are capable of being shorted by a sliding bar 3 in a conventional mannor for regulating the speed of motors. As the sliding bar 3 ,is moved toward the motor M to v2 I thereby progressively short out more resistance from the secondary, the motor accelerates until all of the resistance has been shorted out, at which time the motor is up to full speed.

Connected to line L is one side of a normally closed momentary open stop switch 5. The other side of said switch 5 is connected to line L through a normally open momentary closed run switch 1 and winding 9 of an electromagnetic switch ICR. Connected in electrical parallel with switch I is a normally open contact 9 of switch ICR, thus providing a conventional maintaining circuit tor said winding 9. Normally open contact 9 of switch ICE is connected from a point common to switches 5 to l to line L through the winding :H of an electromagnetic switch 20R. To said common point is also connected one side of anormally closed contact I of switch F. The contact i is responsive to energization of winding .l and is equipped with a timing mechanism, here illustrated as a dashpot 13, so that said contact i opens due to the eiiect :01 spring I5 after a predetermined time interval following initial energization of winding 1. The dash-pot timing mechanism l3, of course, is only illustrative, it being realized that many types of time delay structures and late opening contacts are common to one skilled in the art of electrical controls.

Also connected between a, point common to switches 5 and l and line L are a normally open contact li or switch 20R and winding .1 of switch F. One side of a normally open momentary closed inch switch I! is connected to the above-mentioned point common to switches 5 and 1 while the other side thereof is connected to a point common to winding l l and contacts 9' and H.

The operation of the preferred embodiment will now be explained. To cause the motor M to run continuously, the run button 1 is momentarily depressed thereby completing a circuit from line L through stop switch 5, run switch I and Winding 9 to the line L The energization of winding 9 causes contacts 9* and S to close. The closure or contact 9 provides a maintaining circuit from lin L through stop switch 5, contact 9 and winding 9 to line L thereby maintaining said winding 5 energized following release of run button l. The closure of contact 9 provides energi-zation of winding H by means of a circuit from line L through switch 5, contact 9' and winding H to L Such energization of Winding ll closes contacts H and N Closure of the latter contact provides energization of winding 1 due to the completion of a circuit composed of switch 5.,

contact II and winding I. Contacts I, l and 1 of switch F are then closed due to the energization of winding I, thus establishing polyphase power on the primary P of motor M. The positions of contacts i and H are immaterial during continuous run of the motor since the closure of contact 9 assures continued energization of winding I I. After power has been applied to the motor primary the sliding bar 3 can be manipulated in a well known manner to provide acceleration of the motor until full speed has been reached.

To remove the electrical power from the motor primary P, the stop switch 5 is momentarily depressed thereby removing the electrical power from all of the control circuits and affording deenergization of winding l.

Inching or jogging of the motor is accomplished by depressing the inch button IT. This completes a circuit from line L through switches 5 and i1 and winding H to Line L The contacts H and ll are thus closed due to the energization of winding H and respectively provide a maintaining circuit for winding H and an energizing circuit for winding I. The maintaining circuit consists of switch 5, contacts I and ll and winding II. The energizing circuit for winding I consists of switch 5, contact II and the winding 1. The energization of winding i closes contacts l l and I thus providing electrical power to the motor primary. The secondary S of the motor M thus rotates until the contact i is opened at the end of a predetermined time interval following the initial en ergization of winding I. The opening of contact i opens the above-mentioned maintaining circuit for winding ll, thus causing contacts li and H to open. The opening of contact ll provides removal of power from the motor primary P due to the deenergization of winding l. The secondary S is thereby inched or jogged for a constant and predetermined distance following momentary closure of inch switch ll.

Should it be desirable to inch for a time interval longer than permitted by the timing mechanism, the inch switch ll must be manually closed for the desired length of time. In this manner the winding H will not be deenergized when contact I automatically opens, but instead the inch switch I! will complete a circuit to supply power to said winding II. The opening of switch ll will then, of course, deenergize windings II and I, thus removing the electrical power from the motor primary P.

The above described embodiment of the invention is also advantageous when applied to the usual inching operation where the amount of inching is manually controlled by the length of closure of the inch switch. For such an application, the timing mechanism I3 would be adjusted so that contact l would open an extremely short time interval following energization of winding 1 to thereby provide a wide range of operator controlled inching. The use of timing means of very short timing duration would then insure complete seating of the main power contacts every time the main contactor operated. Complete closure is very desirable, if not essential, in that welding of the main contacts will result if sufficient force is not built up upon closure of the contacts to provide rapid opening thereof when the winding i is deenergized. It is deemed apparent to one skilled in the art that for such application "long wipe or late opening contacts could be used to great advantage in place 4 of the timing mechanism l3 and contact I as illustrated.

I claim:

1. The combination with an electric motor and a source of electric power, of electromagnetic switching means energizable to establish power connections between the motor and said source, an electromagnetic relay energizable to effect energization of said switching means, means including a switch operable to energize said relay, means including means responsive to operation of said switch to establish a holding circuit for said relay, a second switch operable to interrupt said holding circuit, means including a third switch operable to energize said relay, and means including means responsive to operation of said relay to establish another holding circuit for said relay and further including timing means acting a predetermined interval following operation of said third switch to interrupt the last mentioned holding circuit.

2. The combination with an electric motor and a source of electric power, of electromagnetic switching means energizable to establish power connections between the motor and said source, an electromagnetic relay energizable to effect energization of said switching means, means including a switch operable to energize said electromagnetic switch and establish a holding circuit for said electromagnetic switch, means including a second switch operable to energize said electromagnetic switch and establish a second holding circuit for said electromagnetic switch and further including timing means acting a predetermined interval following operation of said switch to interrupt said second holding circuit, and means including a third switch operable to interrupt either of said holding circuits at will.

3. The combination with a motor, an electromagnetic switch energizable to establish power connections for said motor, and normal run control means including a switch operable to energize said electromagnetic switch and complete a holding circuit for the latter, of inching control means including a second switch operable to energize said electromagnetic switch and establish another holding circuit for the latter and further including timing means acting a predetermined interval following operation of said second switch to interrupt the last mentioned holding circuit.

4. In combination, an electric motor, an electro-responsive switch operable to complete power connections to said motor upon energization of its control winding and having a normally closed auxiliary contact opening a predetermined interval following energization of said control winding, a relay energizable to complete power connections to the control winding of said switch, and having an auxiliary contact, inching control means comprising means operable to initiate the energization of said relay and a holding circuit for the control winding of said relay inclusive of the auxiliary contacts of said switch and said relay, running control means for said relay comprising means operable to energize and complete another holding circuit for the control winding of said relay, and means operable at will to interrupt either of said holding circuits.

5. In combination, an electric motor, a source of electric power, an electromagnetic switch energizable to complete power connections to said motor from said source and having a normally closed auxiliary contact opening a predetermined interval following energization of said switch, a

relay energizable to complete power connections to the control winding of said electromagnetic switch and having a normally open auxiliary contact, inching control means comprising a normally open switch operable to complete an energizing circuit for the control winding of said relay, means inclusive of the auxiliary contacts of said electromagnetic switch and said relay for effecting establishment of a holding circuit for the control winding of said relay interruptible by Opening of the auxiliary contact of said electromagnetic switch, running control means comprising a second normally open switch operable to complete power connections to said relay and means including a second relay responsive to 010- 15 eration of said second normally open switch to establish a second holding circuit for the first mentioned relay and a holding circuit for itself, and a normally closed switch operable to inter- 5 rupt at will any of said holding circuits.

References Cited in the file of this patent UNITED STATES PATENTS 10 Number Name Date 1,775,730 McNicol Sept. 16, 1930 2,387,358 Rouse Oct. 23, 1945 2,497,842 Armitage et a1. Feb. 14, 1950 2,519,216 Armstrong Aug. 15, 1950 

